Tactual picture recognition in congenitally blind and sighted children

Three experiments were carried out to investigate tactual processing of two-dimensional raised line drawings by blind and blindfolded sighted children. The results showed an unexpected but consistent pattern indicating that the introduction of ‘meaning’ facilitated the performance of the blindfolded sighted children but caused a relative decline in the performance of the congenitally blind. A general lack of evidence distinguishing between recognition of objects that had or had not been directly experienced through touch suggested that the internal spatial representations of objects depended not only on perceptual information but also on knowledge derived from other sources.